Crystalline Modifications of Pyraclostrobin

ABSTRACT

The present invention relates to novel crystalline modifications of pyraclostrobin, to processes for their preparation and to the use of the novel modifications for preparing crop protection compositions.

The present invention relates to novel crystalline modifications ofpyraclostrobin, to processes for their preparation and to the use of thenovel modifications for preparing crop protection compositions.

Pyraclostrobin (methylN-[[[1-(4-chlorophenyl)pyrazol-3-yl]oxy]-o-tolyl]-N-methoxy-carbamate)is an active compound for controlling phytopathogenic fungi (see, forexample, WO 96/01256 and Herms, S., Seehaus, K., Koehle, H., andConrath, U. (2002) Pyraclostrobin—“More than just a Fungicide”Phytomedizin 32: 17). Commercially available pyraclostrobin is anamorphous substance of low melting point. Owing to this property,commercially available pyraclostrobin is not suitable for preparingaqueous suspension concentrates (SC) in a conventional manner, since thegrinding apparatus will get stuck during grinding as a result of thetackiness of the substance. For this reason, commercial preparation byconventional means of biologically and economically interesting mixedproducts of pyraclostrobin with other crop protection agents in the formof suspension concentrates has hitherto not been possible.

For this reason, pyraclostrobin is frequently formulated in the form ofsolvent-comprising emulsion concentrates or suspoemulsion concentratesor in the form of water-dispersible granules. However, emulsionconcentrates and suspoemulsion concentrates comprise relatively largeamounts of organic, water-immiscible solvents, for example aromatichydrocarbons, so that these formulations are problematic both forenvironmental protection reasons and for work hygiene reasons. Moreover,in the case of pyraclostrobin suspoemulsion concentrates, activecompound particles may separate off during storage under certainconditions.

WO 03/082013 proposes the preparation of active compound particles byapplying a pyraclostrobin melt to a carrier material. Using theresulting adsorbates, suspension concentrates, into which mixingpartners may also be introduced, can be prepared by customary processes.However, in these suspension concentrates, there may be an irreversibleparticle size increase of the dispersed active compound particles aftersome time, in particular on storage at elevated temperature. This has apronounced negative effect on the quality of the product. Moreover, theprocess is relatively complicated since it requires additional materialsand process steps.

Accordingly, it is an object of the present invention to providepyraclostrobin in a form which permits the preparation of suspensionconcentrates having improved stability.

This object is achieved by the crystalline modifications II and IV,described in more detail below, of pyraclostrobin.

Thus, the invention relates firstly to a crystalline modification IV ofpyraclostrobin which, in an X-ray powder diffractogram at 25° C., showsat least three, in particular at least 4 and preferably all of thefollowing reflexes:

-   -   d=6.02±0.01 Å    -   d=4.78±0.01 Å    -   d=4.01±0.01 Å    -   d=3.55±0.01 Å    -   d=3.01±0.01 Å.

Crystalline pyraclostrobin of modification IV has typically a meltingpoint in the range from 62 to 72° C., in particular in the range from 64to 68° C. and especially in the range from 65 to 67° C. The heat offusion, i.e. the amount of energy required for melting the crystallinemodification IV, is about 72 to 78 J/g and in particular about 74±1 J/g.The melting points and heats of fusion indicated here refer to valuesdetermined by differential calorimetry (Differential Scanningcalorimetry: DSC, crucible material aluminum, heating rate 5 K/min).

Studies of single crystals of modification IV show that the basiccrystal structure is monoclinic and has the space group P2(1)/c. Thecharacteristic data of the crystal structure of modification IV areshown in Table 1:

TABLE 1 Crystallographic data of modification IV Parameter ModificationIV Class Monoclinic Space group P2(1)/c a 998.5(3) pm b 4780.4(10) pm c788.6(2) pm α 90° β     105.357(6)° γ 90° Volume 3.6301(16) nm³ Z 8Density (calculated) 1.419 g/cm³ R1, wR2 0.0651, 0.1574 a, b, c = Lengthof the edges of the unit cell α, β, γ = Angles of the unit cell Z =Number of molecules in the unit cell

The crystalline modification. IV of pyraclostrobin can be prepared usinga process (hereinbelow also referred to as process IVa), which comprisesthe following steps:

-   i) dissolving a pyraclostrobin form different from modification IV    in an organic solvent or solvent mixture, where the organic solvent    or solvent mixture comprises at least 70% by volume of at least one    fully water-miscible organic solvent L1 and if appropriate up to 30%    by volume of water; and-   ii) effecting crystallization of pyraclostrobin over a period of at    least 10 h, in particular at least 15 h and especially at least 20 h    and/or in the presence of seed crystals of modification IV.

Suitable pyraclostrobin forms different from modification IV are, forexample, a solid or liquid pyraclostrobin melt, amorphous pyraclostrobinor a pyraclostrobin of modifications I, II or III, or mixtures thereof.In a preferred embodiment, a melt of the pyraclostrobin is dissolved inone of the abovementioned organic solvents or solvent mixtures. Thepyraclostrobin used preferably has a purity of at least 90%, inparticular at least 95% and especially at least 98%.

Solvent L1 may be a pure solvent L1 or a mixture of different solventsL1. According to the invention, solvent L1 is fully miscible with water.This is to be understood as meaning that, at 25° C. (and 1023 mbar), thesolvent is fully miscible with water, i.e. does not have a miscibilitygap with water at the temperature mentioned. Preferred are solvents L1which are fully miscible with water at 1023 mbar over a relatively largetemperature range, in particular the entire temperature range relevantfor the crystallization, i.e. the range from 0 to 80° C., but at leastthe temperature range from 10 to 60° C., i.e. do not have a miscibilitygap with water in these temperature ranges. The person skilled in theart is familiar with suitable solvents, which can be found in thespecialist literature and appropriate reference books, such as theHandbook of Chemistry and Physics, CRC Press, Ullmanns Encyclopedia ofIndustrial Chemistry, 5th ed. on CD ROM, Wiley-VCH, 1997 (chapterSolvents) and Industrial Solvents Handbook, 2nd ed. Marcel Dekker 2003.Preference is furthermore given to solvents L1 whose boiling point atatmospheric pressure is in the range from 50 to 100° C.

Preferred solvents L1 are C₁-C₄-alkanols, such as methanol, ethanol,n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol andtert-butanol, and also acetone and butanone, and mixtures thereof.Particularly preferred solvents L1 are methanol, ethanol, n-propanol andisopropanol and mixtures thereof, and especially methanol and ethanoland mixtures thereof, furthermore acetone and butanone.

In addition to the solvent L1, the solvent or solvent mixture used fordissolving the pyraclostrobin may comprise further solvents differentfrom L1. Typical further organic solvents which can be used in a mixturewith the solvent L1 are, for example:

-   -   alkanols having at least 5 carbon atoms, in particular 5 to 12        carbon atoms, such as amyl alcohol, isoamyl alcohol, hexanols,        such as n-hexanol, 2-ethyl-1-butanol, 4-methyl-2-pentanol,        2-ethylhexanol, isononanol, n-nonanol, technical-grade mixtures        of isomeric nonyl alcohols, 2-propylheptanol, isotridecanol,        technical-grade mixtures of isomeric isotridecanols, and the        like;    -   cycloalkanols having at least 5 carbon atoms, in particular 5 to        12 carbon atoms, such as cyclopentanol, cyclohexanol,        cycloheptanol, 2-, 3- and 4-methylcyclohexanol,        3,3,5-trimethylcyclohexanol and the like;    -   aliphatic and cycloaliphatic ketones having 3 to 12 carbon        atoms, such as acetone, methyl ethyl ketone, diethyl ketone,        methyl propyl ketone, methyl butyl ketone, methyl isobutyl        ketone, cyclohexanone, methylcyclohexanone,        dimethylcyclohexanone, 3,3,5-trimethylcyclohexanone, isophorone        and the like;    -   C₁-C₈-alkyl esters and C₅-C₁₀-cycloalkyl esters of aliphatic        C₁-C₄-carboxylic acids, in particular of acetic acid, such as        methyl acetate, ethyl acetate, n-propyl acetate, n-butyl        acetate, isobutyl acetate, sec-butyl acetate, n-amyl acetate,        isoamyl acetate, hexyl acetate, 2-ethylhexyl acetate, octyl        acetate, cyclohexyl acetate, 2-butoxyethyl acetate, and the        corresponding propionates and butyrates;    -   diols having 2 to 8 carbon atoms, in particular glycol,        propanediol, butanediol, hexanediol, 2-ethylhexane-1,3-diol and        2,4-diethyloctane-1,5-diol;    -   N-di-C₁-C₄-alkylamides of aliphatic carboxylic acids and        C₁-C₄-alkyllactams, such as N,N-dimethylformamide,        N,N-dimethylacetamide, N-methylpyrrolidone, N-ethylpyrrolidone        and the like; and also    -   aromatic hydrocarbons, in particular mono- or        di-C₁-C₄-alkyl-substituted benzene, especially toluene and        xylenes.

The proportion of the solvents different from L1 and in particular fromC₁-C₄-alkanols will preferably not exceed 30% by volume, in particular20% by volume, particularly preferably 10% by volume and especially 5%by volume, based on the total amount of the solvent used for dissolvingpyraclostrobin.

In process IVa, for dissolving the pyraclostrobin in step i), use ismade in particular of methanol, ethanol or a mixture of organic solventswhich comprises at least 70% by volume, in particular at least 80% byvolume and especially at least 90% by volume of at least oneC₁-C₄-alkanol selected from the group consisting of methanol andethanol.

In addition to the organic solvents mentioned above, the organic solventused for dissolving the pyraclostrobin may comprise up to 30% by volume,preferably not more than 20% by volume, in particular not more than 10%by volume or not more than 5% by volume, for example from 0.1 to 20% byvolume or from 0.1 to 10% by volume and especially from 0.2 to 5% byvolume, of water.

For dissolving the pyraclostrobin form different from modification IV,the pyraclostrobin will usually be incorporated into the solvent as afinely divided solid or as a melt with mixing at a temperature where thesolvent or solvent mixture is capable of completely dissolving thepyraclostrobin. In a preferred embodiment of the invention, thepyraclostrobin is dissolved at elevated temperature, in particular atleast 50° C., especially at least 55° C., where the temperature used fordissolution will, of course, not exceed the boiling point of thesolvent. Frequently, temperatures in the range from 50 to 100° C., inparticular in the range from 55 to 90° C. and particularly preferably inthe range from 60 to 80° C. are used for the dissolution. The amount ofpyraclostrobin dissolved in solvent L1 depends, of course, on the natureof the solvent L1 and on the dissolution temperature and is frequentlyin the range from 100 to 800 g/l, in particular in the range from 120 to700 g/l. The person skilled in the art will be able to determinesuitable conditions by standard experiments.

The pyraclostrobin is then crystallized. Crystallization can be achievedin a customary manner, for example by cooling the solution obtained instep i), by adding a solvent which reduces the solubility, in particularby adding water, or by concentrating the solution, or by a combinationof the measures mentioned above.

To achieve a conversion into modification IV which is as complete aspossible, the crystallization is carried out over a period (duration ofcrystallization) of at least 15 h, in particular at least 20 h, and/orin the presence of seed crystals of modification IV.

Duration of crystallization is understood by the person skilled in theart as meaning the period of time between the beginning of the measurewhich initiates crystallization and the isolation of the pyraclostrobinby separating the crystalline material from the mother liquor.

In general, the crystallization is allowed to proceed to a point whereat least 80%, preferably at least 90%, in particular at least 95% byweight, for example from 95 to 99.8% by weight, of the pyraclostrobinemployed has crystallized out.

If seed crystals are added during the crystallization, their amount istypically from 0.001 to 10% by weight, frequently from 0.005 to 5% byweight, in particular from 0.01 to 1% by weight and especially from 0.05to 0.5% by weight, based on the pyraclostrobin dissolved. In this case,the duration of crystallization is typically at least 2 h, in particularat least 4 h and especially at least 5 h; however, the crystallizationcan also be carried out over a relatively long period of time of up to anumber of days, for example 2 to 3 days. However, frequently theduration of crystallization will not exceed 24 h and especially 14 h.Accordingly, the crystallization is generally carried out over a periodof from 2 h to 2 d, frequently from 4 to 24 h and in particular from 5 hto 14 h.

If the crystallization of modification IV is carried out in the absenceof seed crystals, the duration of crystallization is generally at least10 h, in particular at least 15 h, especially at least 20 h, and willgenerally not exceed 21 d, frequently 7 d.

In a preferred embodiment of the invention, the pyraclostrobin isdissolved at elevated temperature, preferably at least 50° C., forexample at from 50 to 100° C., preferably from 55 to 90° C. andparticularly preferably in the range from 60 to 80° C., andcrystallization of the pyraclostrobin is then effected by cooling thesolution. Preferably, the pyraclostrobin solution is cooled by at least20 K, in particular by 30 to 50 K, to initiate crystallization. Coolingmay be carried out in a controlled manner, i.e. the solution is cooledusing a low cooling rate of generally not more than 20 K/h, for examplefrom 0.5 to 20 K/h and frequently from 1 to 15 K/h. Controlled coolingis advantageously carried out when the crystallization begins. However,it is also possible to cool more rapidly, in which case the crystalswill be agitated over a relatively long period of time in the motherliquor, i.e. until the desired duration of crystallization is reached,prior to isolation.

If the crystallization is carried out in the presence of seed crystalsof modification IV, these are preferably added only at a temperaturewhere the saturation concentration of pyraclostrobin in the solvent inquestion has been reached, i.e. at or below the temperature where thedissolved amount of pyraclostrobin forms a saturated solution in thesolvent in question. The temperature dependence of the saturationconcentration in a solvent can be determined in standard experiments bythe person skilled in the art. Frequently, the seed crystals are addedwhen the temperature of the solution is not more than 50° C. and inparticular not more than 40° C. After addition of the seed crystals, thesolution is preferably allowed to cool to temperatures below 30° C., inparticular of 25° C. or below, for example to temperatures in the rangefrom 5° C. to 25° C., before the resulting crystalline material isseparated from the mother liquor to isolate the modification IV ofpyraclostrobin. Cooling in the presence of seed crystals can be carriedout in a controlled manner using a cooling rate of generally not morethan 30 K/h, for example from 1 to 30 K/h, frequently from 2 to 20 K/hand in particular from 3 to 15 K/h, or in an uncontrolled manner.

It has been found to be advantageous to agitate the crystalline materialfor an extra period of time at temperatures below the crystallizationtemperature, for example in the range from 10 to 35° C., in the motherliquor, for example from 1 h to 124 h or from 2 h to 96 h, to ensurecomplete conversion into modification IV. In this case, the totalduration from beginning of the cooling to the isolation of the crystalsby removal of the mother liquor is then in the ranges mentioned above.

In a particularly preferred embodiment of process IVa, thepyraclostrobin is initially dissolved in the solvent mentioned above, inparticular in a solvent or solvent mixture which comprises at least 70%by volume, frequently at least 80% by volume, in particular at least 90and especially at least 95% by volume of at least one C₁-C₄-alkanolselected from the group consisting of methanol and ethanol, at elevatedtemperature in the temperature ranges mentioned above, in particular atfrom >50 to 90° C. and especially in the range from 60 to 80° C.,followed by cooling of the solution, preferably to a temperature in therange from 20 to 50° C. and in particular to from 30 to 40° C. Coolingis preferably carried out over a relatively long period of time, forexample over a period of from 2 to 24 h, frequently from 4 to 20 h,using a cooling rate of, preferably, from 1 K/h to 20 K/h and inparticular from 3 to 15 K/h. Seed crystals of modification IV are thenadded to the solution cooled in this manner. The solution is then cooledfurther by at least 5 K and in particular by at least 10 K, for exampleby 5 to 40 K and in particular by 10 to 30 K, for example totemperatures of from 0 to 40° C. and in particular to from 5 to 30° C.The second cooling is preferably carried out over a period of from 1 to10 h, in particular from 2 to 6 h, advantageously using a cooling rateof from 2 to 20 K/h and in particular from 3 to 15 K/h. During thiscooling, the pyraclostrobin crystallizes.

Alternatively, the crystallization can also be effected by addition ofwater, for example from 5 to 60% by volume, in particular from 20 to 55%by volume and especially from 30 to 50% by volume, based on the volumeof the solvent or solvent mixture used for dissolving thepyraclostrobin. The addition of water is preferably carried out over arelatively long period of time, for example over a period of from 30 minto 10 h, in particular over a period of from 1 h to 8 h. In particular,the addition of water and the addition of seed crystals will becombined. The water may be added in the form of pure water or in theform of a mixture of water with one of the solvents L1 mentioned aboveor in a mixture with an organic solvent mixture which comprisespredominantly L1, i.e. at least 70% by volume of L1, based on theorganic solvent, in particular in a mixture with the solvent used forthe dissolution. In the latter case, the proportion of organic solventin the added water-containing mixture is typically in the range from 10to 70% by volume, in particular from 20 to 60% by volume and especiallyfrom 40 to 50% by volume.

In a particularly advantageous manner, the pyraclostrobin iscrystallized by a combination of cooling and addition of water. Inparticular, a crystallization of the pyraclostrobin is initiallyeffected by cooling, preferably with addition of seed crystals, in themanner described above, and the crystallization of the pyraclostrobin isthen brought to completion by addition of water in the amounts mentionedabove. In particular, the water will be added at a temperature at whichpart of the pyraclostrobin present in the solution, for example from 5to 90% by weight and in particular from 10 to 80% by weight, has alreadycrystallized. The water is added in particular at temperatures in therange from 5 to 40° C. and especially in the range from 10 to 30° C. Inparticular, water will be added such that the amount of water, based onthe total amount of solvent+water, is in the range from 20 to 55% byvolume and especially from 30 to 50% by volume. Water is added, inparticular, over a period of from 30 min to 8 h and particularlypreferably over a period of from 1 h to 5 h.

The modification IV is isolated using customary techniques forseparating solid components from liquids, for example by filtration,centrifugation or decanting. In general, the isolated solid will bewashed, for example with the solvent used for the crystallization, withwater or with a mixture of the organic solvent used for thecrystallization with water. The washing can be carried out in one ormore steps, and frequently, the last washing step is carried out withwater. The washing is typically carried out at temperatures of below 30°C., frequently below 25° C. and in particular below 20° C., to keep theloss of the product of value as low as possible. The resultingmodification IV can then be dried and subjected to further processing.However, frequently, the moist active compound obtained after washing,in particular a water-moist active compound, will be subjected tofurther processing.

In another process for preparing the crystalline modification IV ofpyraclostrobin (hereinbelow also referred to as process IVb), thefollowing steps are carried out:

-   i) preparing a suspension of a pyraclostrobin form different from    modification IV in an organic solvent (solvent L2);-   ii) if appropriate, adding seed crystals of modification IV to the    suspension;-   iii) agitating the suspension until at least 90% of the    pyraclostrobin is present in the form of modification IV.

In process IVb, in principle, it is possible to use all forms ofpyraclostrobin different from modification IV mentioned for process IVa.With respect to purity, what was said for process IVa applies.

The solvent L2 is typically an organic solvent or solvent mixturecapable of dissolving the pyraclostrobin at least partially, ifappropriate at elevated temperature. It is in particular an organicsolvent or solvent mixture in which, at a temperature of 40° C.,pyraclostrobin has a solubility of at least 100 g/l and advantageouslyof not more than 800 g/l, in particular of not more than 700 g/l.

Examples of suitable solvents L2 comprise the C₁-C₄-alkanols, alkanolshaving 5 to 12 carbon atoms, cycloalkanols having 5 to 12 carbon atoms,aliphatic and cycloaliphatic ketones having 3 to 12 carbon atoms,C₁-C₈-alkyl esters and C₅-C₁₀-cycloalkyl esters of aliphaticC₁-C₄-carboxylic acids, in particular of acetic acid, diols having 2 to8 carbon atoms, N-di-C₁-C₄-alkylamides of aliphatic carboxylic acids andC₁-C₄-alkyllactams and also aromatic hydrocarbons, in particular mono-or di-C₁-C₄-alkyl-substituted benzene, mentioned among the solvents L1,and mixtures of these solvents.

Advantageously, the organic solvent L2 used for suspending thepyraclostrobin comprises at least 50% by volume, in particular at least60% by volume, particularly preferably at least 70% by volume, veryparticularly preferably at least 80% by volume and especially at least90% by volume of at least one C₁-C₄-alkanol, particularly preferablymethanol, ethanol, n-propanol and isopropanol. Correspondingly, theproportion of solvents different from C₁-C₄-alkanols will preferably notexceed 50% by volume, in particular 40% by volume, particularlypreferably 30% by volume, very particularly preferably 20% by volume,and especially 10% by volume.

In process IVb, for suspending the pyraclostrobin in step i), use ismade, in particular, of isopropanol, ethanol or a mixture of organicsolvents comprising at least 70% by volume, in particular at least 80%by volume, particularly preferably at least 90% by volume, ofisopropanol and/or ethanol.

In addition to the organic solvents mentioned above, the organic solventL2 may comprise small amounts, preferably not more than 25% by volume,in particular not more than 10% by volume and particularly preferablynot more than 5% by volume, of water.

To prepare the suspension, solid or molten pyraclostrobin can besuspended in the solvent L2 in a manner known per se, where thetemperature of the solvent L2 and the amount of pyraclostrobin arechosen such that the pyraclostrobin is not fully dissolved. A personskilled in the art is able to determine these parameters by standardexperiments. Typically, a temperature in the range of from 20 to 40° C.will be chosen. The amount of pyraclostrobin suspended in the solvent L2is frequently in the range from 100 to 800 g/l, in particular in therange from 120 to 700 g/l. Typically, shear forces are used forsuspending the solid or molten pyraclostrobin, for example by stirringthe suspension using a suitable stirrer. Suitable stirrer types arefamiliar to the person skilled in the art, for example from M.Zlokarnik, Stirring, in Ullmann's Encyclopedia of Industrial Chemistry,5th ed. on CD-ROM, Wiley-VCH 1997.

In a preferred embodiment of the invention, the suspension is preparedby initially completely or virtually completely dissolvingpyraclostrobin in the solvent L2, in an advantageous manner by usingelevated temperature, in particular temperatures in the range from 40 to80° C., and then carrying out a partial crystallization of thepyraclostrobin, typically by concentration and/or by lowering thetemperature, typically by at least 10 K, in particular by at least 20 K,for example by from 20 to 50 K.

The suspension obtained in this manner is then, if appropriate withaddition of seed crystals of modification IV, agitated until theconversion into the modification is complete, i.e. the content ofmodification IV in the suspended solid is at least 90% by weight. Thetime required to achieve this can be determined in a standard memo bythe person skilled in the art by taking samples and analyzing thematerial by X-ray powder diffractometry (XRD) or DSC.

If the conversion is carried out with addition of seed crystals, thesuspension will typically be agitated for 12 to 48 h, in particular for14 to 36 h, to achieve the desired conversion, longer periods not beingdisadvantageous. With respect to the amount of seed crystals, what wassaid above for process IVa applies analogously. The seed crystals aretypically added to the suspension at temperatures in the range from 20to 40° C. If the process is carried out without seed crystals, thesuspension will preferably be agitated for at least 24 h, in particularat least 48 h and particularly preferably at least 72 h, before thecrystalline material is separated from the mother liquor.

The temperature of the suspension is advantageously in the range from 20to 40° C. Agitation is typically by stirring.

The isolation of modification IV from the suspension and furtherprocessing can be carried out in the manner described for process IVa.

The processes IVa and IVb according to the invention afford thecrystalline modification IV with a pyraclostrobin content of at least98% by weight, in particular at least 99% by weight. The amount ofmodification IV, based on the total amount of pyraclostrobin, istypically at least 90%, frequently at least 95% and in particular atleast 98%.

In the context of the studies of the crystalline modification IV, threefurther crystalline modifications of pyraclostrobin (modifications I, IIand III) were found. Modifications I, II and III of pyraclostrobin arethermodynamically more stable than amorphous pyraclostrobin, but onlymetastable with respect to modification IV, and under certain conditionsthey are converted into modification. IV. With respect to stability, thefollowing applies: stability (modification I)<stability (modificationII)<stability (modification III)<stability (modification IV).Modifications I, II, III and IV form a monotropic phase system (enthalpyof fusion).

In an X-ray powder diffractogram at 25° C., the crystalline modificationI of pyraclostrobin shows at least four, in particular at least five,frequently at least six and especially all of the following reflexes:

-   -   d=6.57±0.01 Å    -   d=5.80±0.01 Å    -   d=4.78±0.01 Å    -   d=4.22±0.01 Å    -   d=3.96±0.01 Å    -   d=3.52±0.01 Å    -   d=3.42±0.01 Å    -   d=3.34±0.01 Å.

Crystalline pyraclostrobin of modification I typically has a meltingpoint in the range from 55 to 56° C. The heat of fusion, i.e. the amountof energy required for melting the crystalline modification I, is about63 to 66 J/g and in particular about 65±1 J/g.

Modification I of pyraclostrobin is typically obtained on cooling of apyraclostrobin melt when the purity of the pyraclostrobin used forpreparing the melt is at least 95%. By tempering the material attemperatures in the range from 40 to 50° C., crystallization ofmodification I can be accelerated. However, tempering will preferably becarried out for not more than 14 days, since otherwise there will beconversion into the more stable modifications II and III.

In an X-ray powder diffractogram at 25° C., the crystalline modificationII of pyraclostrobin shows at least four, typically at least five,frequently at least six, in particular at least 7 and especially all ofthe following reflexes:

-   -   d=5.93±0.01 Å    -   d=5.82±0.01 Å    -   d=4.89±0.01 Å    -   d=4.78±0.01 Å    -   d=4.71±0.01 Å    -   d=3.97±0.01 Å    -   d=3.89±0.01 Å    -   d=3.77±0.01 Å    -   d=3.75±0.01 Å    -   d=3.57±0.01 Å    -   d=3.43±0.01 Å.

Crystalline pyraclostrobin of modification II typically has a meltingpoint in the range from 57 to 58° C. The heat of fusion, i.e. the amountof energy required for melting the crystalline modification II, is about67 to 70 J/g and in particular about 69±1 J/g.

Studies with single crystals of modification II show that the basiccrystal structure is triclinic and has the space group P-1. Thecharacteristic data of the crystal structure of modification II arelisted in Table 2:

TABLE 2 Crystallographic data of modification II Parameter ModificationIV Class Triclinic Space group P-1 a 789.69(16) pm b 1012.40(14) pm c1228.9(2) pm α 96.733(10)° β 99.833(14)° γ 105.405(12)° Volume 0.9194(3)nm³ Z 2 Density (calculated) 1.401 mg/m³ R1, wR2 0.0606, 0.1414 a, b, c= Length of the edges of the unit cell α, β, γ = Angles of the unit cellZ = Number of molecules in the unit cell

Preparation of the Crystalline Modification II of Pyraclostrobin can beAchieved by a process which comprises the following steps:

-   i) dissolving amorphous pyraclostrobin in an organic solvent    comprising at least 50% by volume of at least one C₁-C₄-alkanol and    preferably not more than 30% by volume, in particular not more than    10% by volume, of water; and-   ii) effecting crystallization of pyraclostrobin over a period of    less than 10 h in the absence of seed crystals of modification IV.

With respect to the dissolution of the pyraclostrobin, in particular thesolvents, the temperatures, concentrations, etc., to be used, what wassaid for process IVa applies in an analogous manner.

Crystallization can, in principle, be effected analogously to themethods illustrated for process IVa. Typically, crystallization will beeffected by cooling the solution by at least 20 K, in particular by 30to 60 K.

In contrast to processes IVa and IVb, the total duration of thecrystallization process, i.e. the period of time between the beginningof the measure which effects crystallization and the isolation of thepyraclostrobin by removal from the mother liquor is less than 10 h, inparticular from 2 h to 8 h.

If appropriate, the crystallization will be carried out in the presenceof seed crystals of modification II. In this case, the amount of seedcrystals is typically from 0.01 to 10% by weight, frequently from 0.02to 5% by weight, in particular from 0.03 to 1% by weight and especiallyfrom 0.05 to 0.5% by weight, based on the dissolved pyraclostrobin. Theseed crystals are typically added during the crystallization ofmodification II and in particular at the beginning of thecrystallization of modification II and preferably at or below thetemperature at which the saturation concentration of pyraclostrobin inthe solvent in question is reached.

In this manner, it is possible to prepare modification II having apyraclostrobin content of at least 98% by weight, in particular at least99% by weight. The proportion of modification II in the crystallinepyraclostrobin prepared in this manner is generally at least 90%.

In an X-ray powder diffractogram at 25° C., the crystalline modificationIII of pyraclostrobin shows at least three, in particular at least four,frequently at least five and especially all of the following reflexes:

-   -   d=5.36±0.01 Å    -   d=5.39±0.01 Å    -   d=4.31±0.01 Å    -   d=3.68±0.01 Å    -   d=3.29±0.01 Å    -   d=2.82±0.01 Å.

Crystalline pyraclostrobin of modification III typically has a meltingpoint in the range from 59 to 60° C. The heat of fusion, i.e. the amountof energy required for melting the crystalline modification I, is about69 to 72 J/g and in particular about 71±1 J/g.

Similarly to the preparation of modification I, preparation ofmodification III is achieved by crystallizing a pyraclostrobin melt,where, in contrast to the preparation of modification I, the melt iskept for a relatively long period of time at temperatures in the rangefrom 18 to 25° C. (ambient temperature), until formation of themodification can be detected in the XRD. The modification can be storedat low temperatures, preferably below −15° C., for example in the rangefrom −18 to −30° C., for a relatively long period of time.

As already mentioned above, modifications II and IV and in particularmodification IV are/is suitable for preparing crop protectioncompositions and in particular for preparing aqueous suspensionconcentrates. Accordingly, the invention also provides a composition forcrop protection, comprising pyraclostrobin in the form of modificationIV or in the form of modification II, if appropriate a liquid phase andalso, if appropriate, customary, generally solid carriers and/orauxiliaries.

Suitable carriers are, in principle, all solid substances usually usedin crop protection compositions, in particular in fungicides. Solidcarriers are, for example, mineral earths, such as silica gels,silicates, talc, kaolin, attaclay, limestone, lime, chalk, bole, loess,clay, dolomite, diatomaceous earth, calcium sulfate and magnesiumsulfate, magnesium oxide, ground synthetic materials, fertilizers, suchas, for example, ammonium sulfate, ammonium phosphate, ammonium nitrate,ureas and products of vegetable origin, such as cereal meal, tree barkmeal, wood meal and nutshell meal, cellulose powders and other solidcarriers.

In the case of liquid formulations of the modifications II and/or IV,the compositions have a liquid phase. Suitable liquid phases are, inprinciple, water and also organic solvents in which pyraclostrobin haslow or no solubility, for example those in which the solubility ofpyraclostrobin at 25° C. and 1013 mbar is not more than 1% by weight, inparticular not more than 0.1% by weight and especially not more than0.01% by weight.

Typical auxiliaries comprise surfactants, in particular the wettingagents and dispersants usually employed in crop protection compositions,furthermore viscosity-modifying additives (thickeners), antifoam agents,antifreeze agents, agents for adjusting the pH, stabilizers, anticakingagents and biocides (preservatives).

The invention relates in particular to compositions for crop protectionin the form of an aqueous suspension concentrate (SC). Such suspensionconcentrates comprise the pyraclostrobin of modification II and/or IV ina finely divided particulate form, where the pyraclostrobin particlesare suspended in an aqueous medium. The size of the active compoundparticles, i.e. the size which is not exceeded by 90% by weight of theactive compound particles, is typically below 30 μm, in particular below20 μm. Advantageously, at least 40% by weight and in particular at least60% by weight of the particles in the SCs according to the inventionhave diameters below 2 μm.

In addition to the active compound, suspension concentrates typicallycomprise surfactants, and also, if appropriate, antifoam agents,thickeners, antifreeze agents, stabilizers (biocides), agents foradjusting the pH and anticaking agents.

In such SCs, the amount of active compound, i.e. the total amount ofpyraclostrobin of modification II and/or IV and, if appropriate, furtheractive compounds is usually in the range from 10 to 70% by weight, inparticular in the range from 20 to 50% by weight, based on the totalweight of the suspension concentrate.

Preferred surfactants are anionic and nonionic surfactants. Suitablesurfactants also include protective colloids. The amount of surfactantswill generally be from 0.5 to 20% by weight, in particular from 1 to 15%by weight and particularly preferably from 1 to 10% by weight, based onthe total weight of the SCs according to the invention. Preferably, thesurfactants comprise at least one anionic surfactant and at least onenonionic surfactant, the ratio of anionic to nonionic surfactanttypically being in the range from 10:1 to 1:10.

Examples of anionic surface-active substances (surfactants) includealkylaryl sulfonates, phenyl sulfonates, alkyl sulfates, alkylsulfonates, alkyl ether sulfates, alkylaryl ether sulfates, alkylpolyglycol ether phosphates, polyaryl phenyl ether phosphates, alkylsulfosuccinates, olefin sulfonates, paraffin sulfonates, petroleumsulfonates, taurides, sarcosides, fatty acids, alkylnaphthalenesulfonicacids, naphthalenesulfonic acids, lignosulfonic acids, condensates ofsulfonated naphthalenes with formaldehyde or with formaldehyde andphenol and, if appropriate, urea, and also condensates of phenolsulfonicacid, formaldehyde and urea, lignosulfite waste liquors andlignosulfonates, alkyl phosphates, alkylaryl phosphates, for exampletristyryl phosphates, and also polycarboxylates, such as, for example,polyacrylates, maleic anhydride/olefin copolymers (for example Sokalan®CP9, BASF), including the alkali metal, alkaline earth metal, ammoniumand amine salts of the substances mentioned above. Preferred anionicsurfactants are those which carry at least one sulfonate group, and inparticular their alkali metal and their ammonium salts.

Examples of nonionic surfactants comprise alkylphenol alkoxylates,alcohol alkoxylates, fatty amine alkoxylates, polyoxyethylene glycerolfatty acid esters, castor oil alkoxylates, fatty acid alkoxylates, fattyamide alkoxylates, fatty polydiethanolamides, lanolin ethoxylates, fattyacid polyglycol esters, isotridecyl alcohol, fatty amides,methylcellulose, fatty acid esters, alkyl polyglycosides, glycerol fattyacid esters, polyethylene glycol, polypropylene glycol, polyethyleneglycol/polypropylene glycol block copolymers, polyethylene glycol alkylethers, polypropylene glycol alkyl ethers, polyethyleneglycol/polypropylene glycol ether block copolymers (polyethyleneoxide/polypropylene oxide block copolymers) and mixtures thereof.Preferred nonionic surfactants are fatty alcohol ethoxylates, alkylpolyglycosides, glycerol fatty acid esters, castor oil alkoxylates,fatty acid alkoxylates, fatty amide alkoxylates, lanolin ethoxylates,fatty acid polyglycol esters and ethylene oxide/propylene oxide blockcopolymers and mixtures thereof.

Typical protective colloids are water-soluble amphiphilic polymers.Examples of these are proteins and denatured proteins, such as casein,polysaccharides, such as water-soluble starch derivatives and cellulosederivatives, in particular hydrophobically modified starches andcelluloses, furthermore polycarboxylates, such as polyacrylic acid andacrylic acid copolymers, polyvinyl alcohol, polyvinylpyrrolidone,vinylpyrrolidone copolymers, polyvinylamines, polyethyleneimines andpolyalkylene ethers.

In particular, the SCs according to the invention comprise at least onesurfactant which improves wetting of the plant parts by the aqueousapplication form (wetting agent) and at least one surfactant whichstabilizes the dispersion of the active compound particles in the SC(dispersant). The amount of wetting agent is typically in the range from0.5 to 10% by weight, in particular from 0.5 to 5% by weight andespecially from 0.5 to 3% by weight, based on the total weight of theSC. The amount of dispersant is typically from 0.5 to 10% by weight andin particular from 0.5 to 5% by weight, based on the total weight of theSC.

Preferred wetting agents are of anionic or nonionic nature and selected,for example, from naphthalenesulfonic acids including their alkalimetal, alkaline earth metal, ammonium and amine salts, furthermore fattyalcohol ethoxylates, alkyl polyglycosides, glycerol fatty acid esters,castor oil alkoxylates, fatty acid alkoxylates, fatty amide alkoxylates,fatty polydiethanolamides, lanolin ethoxylates and fatty acid polyglycolesters.

Preferred dispersants are of anionic or nonionic nature and selected,for example, from polyethylene glycol/polypropylene glycol blockcopolymers, polyethylene glycol alkyl ethers, polypropylene glycol alkylethers, polyethylene glycol/polypropylene glycol ether block copolymers,alkylaryl phosphates, for example tristyryl phosphates, lignosulfonicacids, condensates of sulfonated naphthalenes with formaldehyde or withformaldehyde and phenol and, if appropriate, urea, and also condensatesof phenolsulfonic acid, formaldehyde and urea, lignosulfite wasteliquors and lignosulfonates, polycarboxylates, such as, for example,polyacrylates, maleic anhydride/olefin copolymers (for example Sokalan®CP9, BASF), including the alkali metal, alkaline earth metal, ammoniumand amine salts of the substances mentioned above.

Viscosity-modifying additives (thickeners) suitable for the SCsaccording to the invention are in particular compounds which bestow uponthe formulation pseudoplastic flow properties, i.e. high viscosity inthe resting state and low viscosity in the agitated state. Suitable are,in principle, all compounds used for this purpose in suspensionconcentrates. Mention may be made, for example, of inorganic substances,such as bentonites or attapulgites (for example Attaclay® fromEngelhardt), and organic substances, such as polysaccharides andheteropolysaccharides, such as Xanthan Gum® (Kelzan® from Kelco),Rhodopol® 23 (Rhone Poulenc) or Veegum® (from R.T. Vanderbilt), andpreference is given to using Xanthan-Gum®. Frequently, the amount ofviscosity-modifying additives is from 0.1 to 5% by weight, based on thetotal weight of the SC.

Antifoam agents suitable for the SCs according to the invention are, forexample, silicone emulsions known for this purpose (Silikon® SRE, fromWacker, or Rhodorsil® from Rhodia), long-chain alcohols, fatty acids,defoamers of the type of aqueous wax dispersions, solid defoamers(so-called Compounds), organofluorine compounds and mixtures thereof.The amount of antifoam agent is typically from 0.1 to 1% by weight,based on the total weight of the SC.

Preservatives may also be added for stabilizing the suspensionconcentrates according to the invention. Suitable preservatives arethose based on isothiazolones, for example Proxel® from ICI or Acticide®RS from Thor Chemie or Kathon® MK from Rohm & Haas. The amount ofpreservatives is typically from 0.05 to 0.5% by weight, based on thetotal weight of the SC.

Suitable antifreeze agents are liquid polyols, for example ethyleneglycol, propylene glycol or glycerol. The amount of antifreeze agents isgenerally from 1 to 20% by weight, in particular from 5 to 10% byweight, based on the total weight of the suspension concentrate.

If appropriate, the SCs according to the invention may comprise buffersfor regulating the pH. Examples of buffers are alkali metal salts ofweak inorganic or organic acids, such as, for example, phosphoric acid,boric acid, acetic acid, propionic acid, citric acid, fumaric acid,tartaric acid, oxalic acid and succinic acid.

If the formulations of the crystalline modifications of thepyraclostrobin are used for treating seed, they may comprise furthercustomary components used for treating seed, for example for dressing orcoating. These include, in addition to the components mentioned above,in particular colorants, adhesives, fillers and plasticizers.

Suitable colorants are all dyes and pigments customary for suchpurposes. Both sparingly water-soluble pigments and water-soluble dyescan be used. Examples which may be mentioned are the dyes and pigmentsknown under the names Rhodamine B, C.I. Pigment Red 112 and C.I. SolventRed 1, Pigment blue 15:4, Pigment blue 15:3, Pigment blue 15:2, Pigmentblue 15:1, Pigment blue 80, Pigment yellow 1, Pigment yellow 13, Pigmentred 48:2, Pigment red 48:1, Pigment red 57:1, Pigment red 53:1, Pigmentorange 43, Pigment orange 34, Pigment orange 5, Pigment green 36,Pigment green 7, Pigment white 6, Pigment brown 25, Basic violet 10,Basic violet 49, Acid red 51, Acid red 52, Acid red 14, Acid blue 9,Acid yellow 23, Basic red 10, Basic red 108. The amount of colorant isusually not more than 20% by weight of the formulation and preferably inthe range of from 0.1 to 15% by weight, based on the total weight of theformulation.

Suitable tackifiers are all binders customarily used in seed dressings.Examples of suitable binders include thermoplastic polymers, such aspolyvinylpyrrolidone, polyvinyl acetate, polyvinyl alcohol and tylose,furthermore polyacrylates, polymethacrylates, polybutenes,polyisobutenes, polystyrene, polyethyleneamine, polyethyleneamide, theprotective colloids mentioned above, polyesters, polyether esters,polyanhydrides, polyester urethanes, polyester amides, thermoplasticpolysaccharides, for example cellulose derivatives, such as celluloseesters, cellulose ethers, cellulose ether esters, includingmethylcellulose, ethylcellulose, hydroxymethylcellulose,carboxymethylcellulose, hydroxypropylcellulose and starch derivativesand modified starches, dextrins, maltodextrins, alginates and chitosans,furthermore fats, oils, proteins, including casein, gelatine and zein,gum Arabic, shellac. The tackifiers are preferably compatible withplants, i.e. they have no significant, if any, phytotoxic action. Thetackifiers are preferably biodegradable. Preferably, the tackifier ischosen such that it acts as a matrix for the active components of theformulation. The amount of tackifier is usually not more than 40% byweight of the formulation and preferably in the range of from 1 to 40%by weight and in particular in the range of from 5 to 30% by weight,based on the total weight of the formulation.

In addition to the tackifier, the formulation may also comprise inertfillers. Examples of these are the solid carrier materials mentionedabove, in particular finely divided inorganic materials, such as clays,chalk, bentonite, kaolin, talc, perlite, mica, silica gel, diatomaceousearth, quartz powder, montmorillonite, and also finely divided organicmaterials, such as wood meal, cereal meal, activated carbon and thelike. The amount of filler is preferably chosen such that the totalamount of filler does not exceed 75% by weight, based on the totalweight of all non-volatile components of the formulation. Frequently,the amount of filler is in the range of from 1 to 50% by weight, basedon the total weight of all non-volatile components of the formulation.

In addition, the formulation may also comprise a plasticizer whichincreases the flexibility of the coating. Examples of plasticizers areoligomeric polyalkylene glycols, glycerol, dialkyl phthalates, alkylbenzyl phthalates, glycol benzoates and similar compounds. The amount ofplasticizer in the coating is frequently in the range of from 0.1 to 20%by weight, based on the total weight of all non-volatile components ofthe formulation.

Pyraclostrobin in the form of modification IV or in the form ofmodification II can be used in a manner known per se for controllingphytopathogenic fungi. In particular, it can be formulated together withfurther active compounds, to increase the activity and/or to widen theactivity spectrum. These include, in principle, all insecticides andfungicides which are typically used together with pyraclostrobin. Incrop protection, the novel modifications of pyraclostrobin can be usedas foliar fungicides, as fungicides for seed dressing and as soilfungicides.

They are of particular importance for controlling a large number offungi on various crop plants, such as wheat, rye, barley, triticale,oats, rice, corn, grass, bananas, cotton, soybeans, coffee, sugarcane,grapevines, fruit and ornamental plants and vegetable plants, such ascucumbers, beans, tomatoes, potatoes and cucurbits, and also on theseeds of these plants.

Modifications II and IV are particularly suitable for the jointformulation as suspension concentrates with active compounds which fortheir part can be formulated as suspension concentrates. Accordingly, apreferred embodiment of the invention relates to suspension concentrateswhich, in addition to pyraclostrobin of modification II and/ormodification IV, comprise at least one further active compound in finelydivided, particulate form. With respect to particle sizes, amount ofactive compound and auxiliaries, what was said above applies.

Typical mixing partners of pyraclostrobin are, for example:

-   -   acylalanines, such as benalaxyl, metalaxyl, ofurace, oxadixyl,    -   amine derivatives such as aldimorph, dodine, dodemorph,        fenpropimorph, fenpropidin, guazatine, iminoctadine,        spiroxamine, tridemorph,    -   anilinopyrimidines, such as pyrimethanil, mepanipyrim or        cyprodinyl,    -   antibiotics, such as cycloheximide, griseofulvin, kasugamycin,        natamycin, polyoxin or streptomycin,    -   azoles, such as bitertanol, bromoconazole, cyproconazole,        difenoconazole, diniconazole, epoxiconazole, fenbuconazole,        fluquinconazole, flusilazole, hexaconazole, imazalil,        metconazole, myclobutanil, penconazole, propiconazole,        prochloraz, prothioconazole, tebuconazole, triadimefon,        triadimenol, triflumizole, triticonazole,    -   dicarboximides, such as iprodione, myclozolin, procymidone,        vinclozolin,    -   dithiocarbamates, such as ferbam, nabam, maneb, mancozeb, metam,        metiram, propineb, polycarbamate, thiram, ziram, zineb,    -   heterocyclic compounds, such as anilazine, benomyl, boscalid,        carbendazim, carboxin, oxycarboxin, cyazofamid, dazomet,        dithianon, famoxadone, fenamidone, fenarimol, fuberidazole,        flutolanil, furametpyr, isoprothiolane, mepronil, nuarimol,        probenazole, proquinazid, pyrifenox, pyroquilon, quinoxyfen,        silthiofam, thiabendazole, thifluzamide, thiophanate-methyl,        thiophanate-ethyl, tiadinil, tricyclazole, triforine,    -   nitrophenyl derivatives, such as binapacryl, dinocap, dinobuton,        nitrophthal-isopropyl,    -   phenylpyrroles, such as fenpiclonil or fludioxonil,    -   sulfur,    -   other fungicides, such as acibenzolar-S-methyl, benthiavalicarb,        carpropamid, chlorothalonil, cymoxanil, diclomezine, diclocymet,        diethofencarb, edifenphos, ethaboxam, fenhexamid, fentin        acetate, fenoxanil, ferimzone, fluazinam, fosetyl,        fosetyl-aluminum, iprovalicarb, hexachlorobenzene, metrafenone,        pencycuron, propamocarb, phthalide, toloclofos-methyl,        quintozene, zoxamide,    -   sulfenic acid derivatives, such as captafol, captan,        dichlofluanid, folpet, tolylfluanid,    -   cinnamides and analogs, such as dimethomorph, flumetover or        flumorph,    -   6-aryl[1,2,4]triazolo[1,5-a]pyrimidines as described, for        example, in WO 98/46608, WO 99/41255 or WO 03/004465, in each        case by the formula I,    -   amide fungicides, such as cyflufenamid, and also        (Z)—N-[α-(cyclopropylmethoxyimino)-2,3-difluoro-6-(difluoromethoxy)benzyl]-2-phenylacetamide.

Preferred mixing partners of pyraclostrobin are: metalaxyl, dodemorph,fenpropimorph, fenpropidin, guazatine, spiroxamine, tridemorph,pyrimethanil, cyprodinyl, bitertanol, bromoconazole, cyproconazole,difenoconazole, dinitroconazole, epoxiconazole, fenbuconazole,fluquinconazole, flusilazole, hexaconazole, imazalil, metconazole,myclobutanil, penconazole, propiconazole, prochloraz, prothioconazole,tebuconazole, triadimefon, triadimenol, triflumizole, triticonazole,iprodione, vinclozolin, maneb, mancozeb, metiram, thiram, boscalid,carbendazim, carboxin, oxycarboxin, cyazofamid, dithianon, famoxadone,fenamidone, fenarimol, flutolanil, quinoxyfen, thiophanate-methyl,thiophanate-ethyl, triforine, dinocap, nitrophthal-isopropyl,phenylpyrroles, such as fenpiclonil or fludioxonil,acibenzolar-S-methyl, benthiavalicarb, carpropamid, chlorothalonil,cyflufenamid, cymoxanil, fenhexamid, fentinacetate, fenoxanil,fluazinam, fosetyl, fosetyl-aluminum, iprovalicarb, metrafenone,zoxamide, captan, folpet, dimethomorph, azoxystrobin, dimoxystrobin,fluoxastrobin, kresoxim-methyl, metominostrobin, orysastrobin,picoxystrobin or trifloxystrdbin.

Particularly preferred mixing partners are metalaxyl, fenpropimorph,fenpropidin, guazatine, spiroxamine, pyrimethanil, cyprodinyl,cyproconazole, difenoconazole, epoxiconazole, fenbuconazole,fluquinconazole, flusilazole, hexaconazole, metconazole, myclobutanil,propiconazole, prochloraz, prothioconazole, tebuconazole, triticonazole,iprodione, vinclozolin, boscalid, carbendazim, carboxin, oxycarboxin,cyazofamid, dithianon, quinoxyfen, thiophanate-methyl,thiophanate-ethyl, dinocap, nitrophthal-isopropyl, fenpiclonil orfludioxonil, benthiavalicarb, carpropamid, fenhexamid, fenoxanil,fluazinam, iprovalicarb, metrafenone, zoxamide, dimethomorph,azoxystrobin, dimoxystrobin, fluoxastrobin, kresoxim-methyl,metominostrobin, orysastrobin, picoxystrobin or trifloxystrobin.

Very particularly preferred mixing partners are fenpropimorph,cyproconazole, difenoconazole, epoxiconazole, fenbuconazole,fluquinconazole, flusilazole, hexaconazole, metconazole, myclobutanil,propiconazole, prochloraz, prothioconazole, tebuconazole, triticonazole,boscalid, dithianon, quinoxyfen, thiophanate-methyl, thiophanate-ethyl,dinocap, fenpiclonil or fludioxonil, benthiavalicarb, carpropamid,fenhexamid, fenoxanil, fluazinam, iprovalicarb, metrafenone, zoxamide,dimethomorph, azoxystrobin, dimoxystrobin, fluoxastrobin,kresoxim-methyl, metominostrobin, orysastrobin, picoxystrobin ortrifloxystrobin.

Using the formulations according to the invention of the crystallinemodifications of pyraclostrobin, it is, in principle, possible tocontrol all harmful fungi which can also be controlled using the knownformulations of pyraclostrobin. Depending on the respective mixingpartner, these are, for example, the following plant diseases:

-   -   Alternaria species on vegetables, oilseed rape, sugarbeets,        soybeans, cereals, cotton, fruit and rice (for example A. solani        or A. alternate on potatoes and other plants),    -   Aphanomyces species on sugarbeet and vegetables,    -   Ascochyta sp. on cotton and rice,    -   Bipolaris and Drechslera species on corn, cereals, rice and lawn        (for example D. teres on barley, D. tritci-repentis on wheat),    -   Blumeria graminis (powdery mildew) on cereals,    -   Botrytis cinerea (gray mold) on strawberries, vegetables,        flowers and grapevines,    -   Bottyodiplodia sp. on cotton,    -   Bremia lactucae on lettuce,    -   Cercospora species on corn, soybeans, rice and sugarbeet (for        example C. beticula on sugarbeet),    -   Cochliobolus species on corn, cereals, rice (for example        Cochliobolus sativus on cereals, Cochliobolus miyabeanus on        rice),    -   Corynespora sp. on soybeans, cotton and other plants,    -   Colletotrichum species on soybeans, cotton and other plants (for        example C. acutatum on various plants),    -   Curvularia sp. on cereals and rice,    -   Diplodia sp. on cereals and rice,    -   Exserohilum species on corn,    -   Erysiphe cichoracearum and Sphaerotheca fuliginea on cucumber        plants,    -   Fusarium and Verticillium species (for example V. dahliae) on        various plants (for example F. graminearum on wheat),    -   Gaeumanomyces graminis on cereals,    -   Gibberella species on cereals and rice (for example Gibberella        fujikuroi on rice),    -   Grainstaining complex on rice,    -   Helminthosporium species (for example H. graminicola) on corn        and rice,    -   Macrophomina sp. on soybeans and cotton,    -   Michrodochium sp. for example M. nivale on cereals,    -   Mycosphaerella species on cereals, bananas and peanuts (M.        graminicola on wheat, M. fijiesis on bananas),    -   Phaeoisaripsis sp. on soybeans,    -   Phakopsara sp. for example P. pachyrhizi and Phakopsara        meibomiae on soybeans,    -   Phoma sp. on soybeans,    -   Phomopsis species on soybeans, sunflowers and grapevines (P.        viticola on grapevines, P. helianthii on sunflowers),    -   Phytophthora infestans on potatoes and tomatoes,    -   Plasmopara viticola on grapevines,    -   Penecilium sp. on soybeans and cotton,    -   Podosphaera leucotricha on apples,    -   Pseudocercosporella herpotrichoides on cereals,    -   Pseudoperonospora species on hops and cucumber plants (for        example P. cubenis on cucumber),    -   Puccinia species on cereals, corn and asparagus (P. triticina        and P. striformis on wheat, P. asparagi on asparagus),    -   Pyrenophora species on cereals,    -   Pyricularia oryzae, Corticium sasakii, Sarocladium oryzae, S.        attenuatum, Entyloma oryzae on rice,    -   Pyricularia grisea on lawn and cereals,    -   Pythium spp. on lawn, rice, corn, cotton, oilseed rape,        sunflowers, sugarbeet, vegetables and other plants,    -   Rhizoctonia-species (for example R. solani) on cotton, rice,        potatoes, lawn, corn, oilseed rape, potatoes, sugarbeet,        vegetables and other plants,    -   Rynchosporium sp. (for example R. secalis) on rice and cereals,    -   Sclerotinia species (for example S. sclerotiorum) on oilseed        rape, sunflowers and other plants,    -   Septoria tritici and Stagonospora nodorum on wheat,    -   Erysiphe (syn. Uncinula necator) on grapevines,    -   Setospaeria species on corn and lawn,    -   Sphacelotheca reilinia on corn,    -   Thievaliopsis species on soybeans and cotton,    -   Tilletia species on cereals,    -   Ustilago species on cereals, corn and sugarbeet and    -   Venturia species (scab) on apples and pears (for example V.        inaequalis on apple).

In a manner known per se, the modifications II and IV according to theinvention of pyraclostrobin can also be formulated with insecticidally,acaricidally or nematicidally active compounds. It has been found to beparticularly advantageous to use modifications II and IV ofpyraclostrobin together with at least one active compound which isactive against stinging, chewing, biting or sucking insects and otherarthropods, for example from the order of the

-   -   Coleoptera, in particular Phyllophaga sp., such as Phyllophaga        cuyabana, Sternechus sp., such as Sternechus pingusi,        Sternechuns subsignatus, Promecops sp. such as Promecops        carinicollis, Aracanthus sp. such as Aracanthus morei, and        Diabrotica sp. such as Diabrotica speciosa, Diabrotica        longicornis, Diabrotica 12-punctata, Diabrotica virgifera,        Oryzophagus sp.,    -   Lepidoptera, in particular Elasmopalpus sp. such as Elasmopalpus        sp. such as Elasmopalpus lignosellus, Diloboderus sp.    -   Isoptera, in particular Rhinotermitida,    -   Homoptera, in particular Dalbulus maidis,        or against nematodes, including root-knot nematodes, for example        Meloidogyne spp., such as Meloidogyne hapla, Meloidogyne        incognita, Meloidogyne javanica, and other Meloidogyne species;        cyste-forming nematodes, such as Globodera rostochiensis and        other Globodera species; Heterodera avenae, Heterodera glycines,        Heterodera schachtii, Heterodera trifolii, and other Heterodera        species; gall nematodes, for example Anguina species; stem        eelworms and foliar nematodes, such as Aphelenchoides species.

A formulation comprising a modification II and/or IV according to theinvention of pyraclostrobin and thiophanate-methyl or thiophanate-ethyl,for example, can be used for controlling the following harmful fungi:

-   -   Alternaria sp. on cereals, cotton and rice    -   Ascochyta sp. on cotton and rice,    -   Botryodiplodia sp. on cotton,    -   Cercospora species on corn, soybeans, rice and other plants,    -   Corynespora sp. on soybeans, cotton and other plants,    -   Colletotrichum species on soybeans, cotton and other plants,    -   Curvularia sp. on cereals and rice,    -   Diplodia sp. on cereals and rice,    -   Drechslera sp. on cereals and rice,    -   Fusarium sp. on cereals, soybeans and cotton,    -   Giberella sp. on cereals and rice,    -   Macrophomia sp. on soybeans and cotton,    -   Penecilium sp. on soybeans and cotton,    -   Phaeoisaripsis sp. on soybeans,    -   Phoma sp. on soybeans,    -   Phomopsis sp. on soybeans,    -   Pythium sp. on soybeans and cotton,    -   Pyrenophora sp.,    -   Pyricularia sp. on rice,    -   Rhizoctonia sp. on soybeans, rice and cotton,    -   Rhychosporium sp. on rice,    -   Septoria sp. on soybeans,    -   Tilletia sp. on cereals and rice,    -   Ustilago sp. on cereals.

A formulation comprising a modification II and/or IV according to theinvention of pyraclostrobin, thiophanate-methyl or thiophanate-ethyl andfipronil or another GABA antagonist, such as acetoprole, endosulfan,ethiprole, vaniliprole, pyrafluprole or pyriprole, for example, can beused for controlling the harmful fungi mentioned above with simultaneouscontrol of insects, for example

-   -   Coleoptera, in particular Phyllophaga sp., such as Phyllophaga        cuyabana, Sternechus sp., such as Sternechus pingusi,        Sternechuns subsignatus, Promecops sp., such as Promecops        carinicollis, Aracanthus sp., such as Aracanthus morei, and        Diabrotica sp., such as Diabrotica speciosa, Diabrotica        longicornis, Diabrotica 12-punctata, Diabrotica virgifera,        Oryzophagus sp., and    -   Lepidoptera, in particular Elasmopalpus sp., such as        Elasmopalpus lignosellus, Diloboderus sp.

A formulation comprising a modification II and/or IV according to theinvention of pyraclostrobin and epoxyconazole, for example, can be usedfor controlling the following harmful fungi:

-   -   Microdochium sp. on cereals.    -   Tilletia sp. on cereals and rice,    -   Ustilago sp. on cereals.

A formulation comprising a modification II and/or IV according to theinvention of pyraclostrobin, triticonazole and prochloraz orprochloraz-CuCl, for example, can be used for controlling the followingharmful fungi:

-   -   Microdochium sp. on cereals,    -   Tilletia sp. on cereals and rice,    -   Ustilago sp. on cereals.

The novel modifications II and IV of pyraclostrobin allow thepreparation of low-solvent or solvent-free aqueous suspensionconcentrates both of pyraclostrobin on its own and of pyraclostrobinwith other crop protection agents, in particular the mixing partnersindicated above. The solvent content, in particular the content ofaromatic hydrocarbons, minus any antifreeze agents, is generally notmore than 2% by weight of the suspension concentrate and is frequentlybelow 2% by weight. The suspension concentrates according to theinvention are distinguished in particular by better storage stabilitycompared to the known pyraclostrobin-comprising suspension concentratesand suspoemulsion concentrates.

The figures and examples below serve to illustrate the invention and arenot to be understood as limiting it.

FIG. 1: X-ray powder diffractogram of modification IV

FIG. 2: X-ray powder diffractogram of modification II

FIG. 3: X-ray powder diffractogram of modification I

FIG. 4: X-ray powder diffractogram of modification III

FIG. 5: Picture of the formulation from formulation example 1 taken witha light microscope after 26 weeks of storage at 40° C.

FIG. 6: Picture of the formulation of comparative formulation exampletaken with a light microscope after 26 weeks of storage at 40° C.

ANALYSIS

The pictures of the X-ray powder diffractograms were taken using aD-5000 diffractometer from Siemens in reflection geometry in the rangefrom 2θ=4°-35° with increments of 0.02° using Cu—Kα radiation at 25° C.The 2θ values found were used to calculate the stated interplanarspacing d.

The crystallographic data of modifications II and IV (Tables 1 and 2)were determined on a single-crystal diffractometer from Siemens usingCu—Kα radiation.

Melting points and heats of fusion were determined by DSC using aSimultaneous Thermal Analyzer STA 449 C Jupiter from NETZSCH with aheating rate of 5 K/min in the range from −5° to +80° C. The amount ofsample was 5 to 10 mg.

The particle sizes in the suspension concentrates were determined usinga Mastersizer 2000 from Malvern Instruments GmbH.

PREPARATION EXAMPLES Example 1 Preparation of PyraclostrobinModification IV by Crystallization from Isopropanol Using Seed Crystalsof Modification IV Practice

600 g of isopropanol are heated to 70° C. Separately, 300 g of amorphouspyraclostrobin are converted at 80° C. into a melt of low viscosity.With vigorous stirring, this melt is added to the isopropanol. Themixture is kept at 70° C. until the material is fully dissolved (about30 minutes). Subsequently, the mixture is allowed to cool to roomtemperature. With stirring, 1 g of crystalline pyraclostrobin ofmodification IV is added. After about 1 hour, crystallization sets in.The mixture is stirred for a further 18 hours and the crystals arefiltered off and dried under reduced pressure at 25° C. Yield: 290 g ofpyraclostrobin. Modification IV was identified by its reflexes in theX-ray powder diffractogram (FIG. 1).

Example 2 Preparation of Pyraclostrobin Modification IV byCrystallization from Ethanol Using Seed Crystals of Modification IV

In a 2.5 l vessel with double mantle and turbine stirrer (PBT turbine),1500 g of ethanol are initially charged and heated to 50° C. 1000 g ofpyraclostrobin are heated to 70° C. and added to the reaction vessel.After 10 min of stirring at 60° C., the resulting clear solution isallowed to cool slowly. At 34° C., 1 g of seed crystals of modificationIV is added. Over a period of 114-116 hours, the mixture is then allowedto cool to ambient temperature. The mixture is then cooled to 10° C. Thesolid is isolated, washed with 400 ml of cold ethanol and, under reducedpressure (40 mbar) and at ambient temperature, dried for a period ofabout 16 hours. Yield: 870 g (melting point 67° C.). Modification IV wasidentified by its reflexes in the X-ray powder diffractogram (see FIG.1).

Example 3 Preparation of Pyraclostrobin Modification Iv byCrystallization from Isopropanol without Seed Crystals

100 g of isopropanol are heated to 60° C. 15 g of pyraclostrobin arethen added and the mixture is stirred until all the material hasdissolved. The mixture is then allowed to cool to ambient temperatureand stirred for another 2 weeks. The crystals are filtered off and driedunder reduced pressure and at ambient temperature for 16 h. Yield: 12 g.

In an X-ray powder diffractometry, the material obtained showed thediagram shown in FIG. 1.

Example 4 Preparation of Pyraclostrobin Modification II byCrystallization from Isopropanol without Seed Crystals

100 g of isopropanol are heated to 60° C. With stirring, 15 g ofpyraclostrobin are then added, and the mixture is stirred until all thematerial has dissolved. The mixture is then allowed to cool to 20° C.and stirred for another 4 hours. The mixture is then cooled to 10° C.and stirred for a further hour. The crystals are isolated immediatelyand dried under reduced pressure and at ambient temperature for 16 h.Yield: 12 g. In an X-ray powder diffractometry, the material obtainedshowed the diagram shown in FIG. 2.

Example 5 Preparation of Pyraclostrobin Modification I byCrystallization from the Melt

Amorphous pyraclostrobin was melted and slowly cooled. Modification Icrystallizes first from the pyraclostrobin melt. The crystallization isaccelerated by tempering at about 40° to 45° C. The material obtainedhas the X-ray powder diffractogram shown in FIG. 3.

Example 6 Preparation of Pyraclostrobin Modification III byCrystallization from the Melt

This modification crystallizes after a number of weeks from apyraclostrobin melt if the melt is kept at a temperature in the rangefrom 18 to 25° C. In an X-ray powder diffractometry, the materialobtained showed the diagram shown in FIG. 4.

Example 7 Preparation of Pyraclostrobin of Modification Iv byCrystallization from Ethanol in the Presence of Seed Crystals

358 g of pyraclostrobin having a purity of 99% were liquefied at 80° C.and stirred with 525 g of ethanol (96%) until the pyraclostrobin wasfully dissolved. Over a period of 5 h, the mixture was then cooled to35° C., and about 1 g of seed crystals of modification IV was added atthis temperature. Over a period of 3 h, the mixture was then cooled to20° C., and 483 g of water were then added over a period of 2 h. Afterthe addition of water had ended, stirring at 20° C. was continued foranother hour and the mixture was then filtered using a notch (porosity4). After washing with 350 g of water, the crystalline solid obtainedwas dried under reduced pressure at 40° C. This gave 353 g of acrystalline product which was identified as modification IV. Yield:98.6%, content: 99.5%, melting point: 63.0° C.

Example 8 Preparation of Pyraclostrobin of Modification Iv byCrystallization from Methanol in the Presence of Seed Crystals

179.4 g of active compound I were liquefied at 80° C. and stirred with253 g of methanol (96%) until the pyraclostrobin was fully dissolved.Over a period of 4 h, the mixture was then cooled to 35° C., and about0.5 g of seed crystals of modification IV was added at this temperature.Over a period of 2 h, the mixture was then cooled to 20° C., and 252 gof water were then added over a period of 1.5 h. After the addition ofwater had ended, stirring at 20° C. was continued for another hour andthe mixture was then filtered using a notch (porosity 4). After washingwith 90 g of water, the crystalline solid obtained was dried underreduced pressure at 40° C. This gave 177.8 g of a crystalline productwhich was identified as modification IV. Yield: 99.1%, content: 99.8%,melting point: 65.0° C.

Example 9 Preparation of Pyraclostrobin of Modification Iv byCrystallization from Methanol in the Presence of Seed Crystals

179.4 g of active compound I were liquefied at 80° C. and stirred with253 g of methanol (96%) until the pyraclostrobin was fully dissolved.Over a period of 3 h, the mixture was then cooled to 35° C., and about0.5 g of seed crystals of modification IV was added at this temperature.Over a period of 2 h, the mixture was then cooled to 20° C., and 252 gof water were then added over a period of 1.5 h. After the addition ofwater had ended, stirring at 20° C. was continued for another hour andthe mixture was then filtered using a notch (porosity 3). After washingwith 90 g of water, the crystalline solid obtained was separated off.This gave 236.4 g of a water-moist crystalline product which had anactive compound content of 75.3%. This corresponds to a yield of 99.2%.A sample of the product obtained was dried under reduced pressure at 40°C. This gave a crystalline product which was identified as modificationIV and had a melting point of 65.2° C.

Comparative Example 1

Crystallization analogously to Example 1 but using ethyl acetate insteadof isopropanol gave a solidifying oil and poor yields of pyraclostrobin.

Comparative Example 2

Crystallization analogously to Example 1 but, in contrast to the methoddescribed therein, without the use of seed crystals gave a solidifyingoil and poor yields of pyraclostrobin.

FORMULATION EXAMPLES Comparative Formulation Example Preparation of aSuspension Concentrate of Pyraclostrobin Adsorbed on Silicic AcidPyraclostrobin Premix

Water (about 60% by weight of the total formulation) is initiallycharged in a suitable vessel. Wetting agent and then silicic acid arestirred in, and the mixture is heated to 80° C. 20 parts by weight of apyraclostrobin melt, heated to 80° C., are then added with stirring, andafter the end of the addition stirring at 80° C. is continued for afurther 30 minutes. With stirring, the suspension is then cooled toambient temperature. The premix had the following composition:

Water 60 parts by weight Wetting agent 5 parts by weight of(naphthalenesulfonic acid/ formaldehyde condensate) Silicic acid 15parts by weight (precipitated silicic acid) Pyraclostrobin 20 parts byweight

Finished Formulation:

Water is initially charged in a suitable vessel. With stirring, wettingagent, dispersant, antifreeze agent, stabilizer and partial amounts ofthe defoamer are then added. The second active compound and thepyraclostrobin premix are added to this mixture. The dispersion is thenground in a bead mill with effective cooling to the desired fineness.

With addition of the remaining formulation auxiliaries (bactericide,thickener, remaining defoamer), the formulation is then finished. Thefinished formulation had the following composition:

Water 42.3 parts by weight Wetting agent 4 parts by weight(naphthalenesulfonic acid/ formaldehyde condensate) Silicic acid 7.5parts by weight (precipitated silicic acid) Pyraclostrobin 10 parts byweight Dispersant 3 parts by weight (EO/PO block copolymer) Antifreezeagent 2 parts by weight (propylene glycol) Defoamer 0.5 part by weight(commercial silicone defoamer, for example Silfoam types from Wacker)Stabilizer 0.2 part by weight (buffer system) Active compound 30 partsby weight (folpet) Bactericide 0.2 part by weight (substitutedisothiazolin-3-ones) Thickener 0.3 part by weight (xanthan gum)

Formulation Example 1 Preparation of a Suspension Concentrate ofPyraclostrobin in Modification IV

The residual amount of water is initially charged in a suitable vessel.The further formulation components: wetting agent, dispersant,antifreeze agent, stabilizer and partial amounts of the defoamer arethen stirred in. Crystalline pyraclostrobin and the second solid activecompound are then added. The dispersion is then ground in a bead millwith effective cooling to the desired fineness. The formulation is thenfinished with addition of the remaining formulation auxiliaries.

Water 46.9 parts by weight Wetting agent 3 parts by weight(naphthalenesulfonic acid/ formaldehyde condensate) Pyraclostrobin 10parts by weight Dispersant 2 parts by weight (polyethyleneoxide/polypropylene oxide block copolymer (EO/PO block copolymer))Antifreeze agent 7 parts by weight (propylene glycol) Defoamer 0.5 partby weight (commercial silicone defoamer, for example Silfoam types fromWacker) Stabilizer 0.1 part by weight (buffer system) Active compound 30parts by weight (folpet) Bactericide 0.2 part by weight (substitutedisothiazolin-3-ones) Thickener 0.3 part by weight (xanthan gum)

To determine the stability, the formulations were stored at 40° C. forthe period stated in Table 3. To determine the particle size by lightscattering, a sample was diluted and dispersed in water, and theparticle size distribution was then determined using the Mastersizer2000.

The light microscope pictures of a 5% strength dilution shown in FIGS. 5and 6 were taken with a Leica microscope using a 3 CCD Color VisionCamera module.

To determine the stability of the dispersion, a 2% strength dilution wasprepared in a 100 ml pointed cylinder. The volume of the sediment formedwas read off after a standing time of 2 hours.

TABLE 3 Storage stability Comparative Formulation example example 1Stability of a 2% dispersion, 2 h after 4 weeks of storage, 0.4 ml ofsediment 0.15 ml of sediment 40° C. after 26 weeks of storage, 0.5 ml ofsediment  0.3 ml of sediment 40° C. Particle size distribution after 4weeks of storage, 40° C. <2 μm ¹⁾ 56% 65% 100%< ²⁾  95 μm 24 μm after 26weeks of storage, 40° C. <2 μm 42% 57% 100%< 172 μm 21 μm ¹⁾ % by weightof particles below 2 μm ²⁾ Maximum particle size

Analogously to Example 1, the following aqueous suspension concentrateswere prepared:

Example 3

Water 42 parts by weight Wetting agent 2.6 parts by weight(naphthalenesulfonic acid/ formaldehyde condensate) Pyraclostrobin 4parts by weight Dispersant 2.7 parts by weight (EO/PO block copolymer)Antifreeze agent 6.3 parts by weight (propylene glycol) Defoamer 0.5part by weight (commercial silicone defoamer, for example Silfoam typesfrom Wacker) Stabilizer 1.4 parts by weight (buffer system) Activecompound 40 parts by weight (folpet) Bactericide 0.2 part by weight(substituted isothiazolin-3-ones) Thickener 0.3 part by weight (xanthangum)

Example 4

Water 47 parts by weight Wetting agent 2 parts by weight(naphthalenesulfonic acid/ formaldehyde condensate) Pyraclostrobin 40parts by weight Dispersant 3 parts by weight (EO/PO block copolymer)Antifreeze agent 7 parts by weight (propylene glycol) Defoamer 0.5 partby weight (commercial silicone defoamer, for example Silfoam types fromWacker) Bactericide 0.2 part by weight (substituted isothiazolin-3-ones)Thickener 0.3 part by weight (xanthan gum)

Example 5

Water 47.1 parts by weight Wetting agent 2 parts by weight(naphthalenesulfonic acid/ formaldehyde condensate) Pyraclostrobin 10parts by weight Dispersant 3 parts by weight (EO/PO block copolymer)Antifreeze agent 7 parts by weight (propylene glycol) Defoamer 0.5 partby weight (commercial silicone defoamer, for example Silfoam types fromWacker) Active compound 20 parts by weight (boscalid) Bactericide 0.2part by weight (substituted isothiazolin-3-ones) Thickener 0.2 part byweight (xanthan gum)

The results of the stability studies are compiled in Table 4.

TABLE 4 Storage stability Example 3 Example 5 Stability of a 2%dispersion, 1 h directly after preparation trace of sediment trace ofsediment after 4 weeks of storage, 20° C. trace of sediment trace ofsediment 40° C. 0.05 ml of sediment trace of sediment after 26 weeks ofstorage, 20° C. trace of sediment trace of sediment 40° C. 0.05 ml ofsediment trace of sediment Particle size distribution directly afterpreparation <2 μm ¹⁾/100%< ²⁾ 76%/11 μm 72%/11 μm after 4 weeks ofstorage at 20° C. <2 μm ¹⁾/100%< ²⁾ 68%/21 μm 63%/15 μm at 40° C. <2 μm¹⁾/100%< ²⁾ 66%/21 μm 40%/21 μm after 26 weeks of storage, at 20° C. <2μm ¹⁾/100%< ²⁾ 67%/24 μm 56%/21 μm at 40° C. <2 μm ¹⁾/100%< ²⁾ 44%/33 μm33%/28 μm ¹⁾ % by weight of particles below 2 μm ²⁾ Maximum particlesize

1. A crystalline modification IV of pyraclostrobin which, in an X-raypowder diffractogram at 25° C., shows at least three of the followingreflexes: d=6.02±0.01 Å d=4.78±0.01 Å d=4.01±0.01 Å d=3.55±0.01 Åd=3.01±0.01 Å.
 2. The crystalline modification IV according to claim 1having a melting point in the range from 62 to 72° C.
 3. The crystallinemodification IV according to claim 1 having a pyraclostrobin content ofat least 98% by weight.
 4. A process for preparing a crystallinemodification IV of pyraclostrobin according to any of the precedingclaims, comprising: i) dissolving a pyraclostrobin form different frommodification IV in an organic solvent or solvent mixture, where theorganic solvent or solvent mixture comprises at least 70% by volume ofat least one fully water-miscible organic solvent L1 and if appropriateup to 30% by volume of water; and ii) effecting crystallization ofpyraclostrobin over a period of at least 10 h and/or in the presence ofseed crystals of modification IV.
 5. The process according to claim 4,where the pyraclostrobin is dissolved at a temperature above 50° C. 6.The process according to claim 5, where, for crystallizing thepyraclostrobin, the solution is cooled.
 7. The process according to anyof claims 4 to 6, where the crystallization of the pyraclostrobin iseffected by adding water to the pyraclostrobin solution.
 8. The processaccording to any of claims 4 to 7, where seed crystals of modificationIV are added during or prior to the crystallization of thepyraclostrobin.
 9. The process according to any of claims 4 to 8, wherethe fully water-miscible organic solvent L1 is selected fromC₁-C₄-alkanols, acetone and butanone.
 10. The process according to claim9, where, in step i), methanol, ethanol or a solvent mixture comprisingat least 70% by volume of methanol and/or ethanol is used for dissolvingthe pyraclostrobin.
 11. The process according to any of claims 4 to 10,where, after crystallization of a partial amount of the pyraclostrobincomprised in the solution, water is added to bring the crystallizationof the pyraclostrobin to completion.
 12. A process for preparing acrystalline modification IV of pyraclostrobin according to any of claims1 to 3, comprising: i) preparing a suspension of a pyraclostrobin formdifferent from modification IV in an organic solvent; ii) ifappropriate, adding seed crystals of modification IV to the suspension;iii) agitating the suspension until at least 90% of the pyraclostrobincomprised therein is present in the form of modification IV.
 13. Theprocess according to claim 12, where the organic solvent used in step i)to suspend the pyraclostrobin comprises at least 50% by volume of atleast one C₁-C₄-alkanol.
 14. The process according to claim 13, wherethe organic solvent used in step i) to suspend the pyraclostrobincomprises at least 70% by volume of methanol, isopropanol and/orethanol.
 15. A crystalline modification II of pyraclostrobin which, inan X-ray powder diffractogram at 25° C., shows at least four of thefollowing reflexes: d=5.93±0.01 Å d=5.82±0.01 Å d=4.89±0.01 Åd=4.78±0.01 Å d=4.71±0.01 Å d=3.97±0.01 Å d=3.89±0.01 Å d=3.77±0.01 Åd=3.75±0.01 Å d=3.57±0.01 Å d=3.43±0.01 Å.
 16. The crystallinemodification according to claim 15 having a melting point in the rangefrom 57 to 58° C.
 17. The crystalline modification according to claim 15or 16 having a pyraclostrobin content of at least 98% by weight.
 18. Aprocess for preparing a crystalline modification II of pyraclostrobinaccording to any of claims 15 to 17, comprising the following steps: i)dissolving amorphous pyraclostrobin in an organic solvent comprising atleast 50% by volume of at least one C₁-C₄-alkanol; and ii) effectingcrystallization of pyraclostrobin over a period of less than 10 h in theabsence of seed crystals of modification IV.
 19. A composition for cropprotection, comprising pyraclostrobin in the form of modification IVaccording to any of claims 1 to 3 or in the form of modification IIaccording to any of claims 15 to 17 and customary carriers and/orauxiliaries.
 20. The composition according to claim 19 in the form of anaqueous suspension concentrate.
 21. The use of pyraclostrobin in theform of modification IV according to any of claims 1 to 3 or in the formof modification II according to any of claims 15 to 17 for controllingphytopathogenic fungi.